Extension-bit



(No Model.)

WHITING.

XTENSION BIT.

Patented Nov. 26, 1889.

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UNITED STATES PATENT OFFICE.

\VILTJIAM b. lVlll'IING, OF XVATER EURY, ASSIGNOR 'lO JAMES SWAN, OF SEYMOUR, (ONNECTICU'II EXTENSION-BIT.

I SPECIFICATION forming part of Letters Patent No. 415,988, dated November 26, 1889.

Application filed August 9, 1889. Serial No. 320,223. (No model.)

To all whom, it may concern:

Be it known that 1, WILLIAM WHITING, a citizen of the United States, residing at \Vatel-bury, in the county of New Haven and State of Connecticut, have invented certain new and useful Improvements in Extension- Bits; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to the class of bits which is provided with detachable and adjustable cutters and spurs, so that the bits may be set to bore holes of any gage between the diameter of the bit proper and the diameter of a circle corresponding to the sweep of the adjustable cutter at the extreme of its outward movement, and has for its object to simplify and cheapen the construction, to per mit the adjustment of the detachable cutter at the exact gage required, and to insure that it shall be absolutely immovable when once adjusted and locked in position, the construction as a whole being inexpensive, strong, durable, and practically impossible to get out of repair.

1V ith these ends in view I have devised the novel construction of which the following description, in connection with the accompanying drawings, is a specification, numbers being used to denote the several parts.

Figures 1 and 2 are opposite side elevations of my novel bit, and Fig. 3 is a section on the line a: 00 in Fig. 2.

1 denotes the shank of the bit; 2, the pod; 3, the delivery-grooves; 4, the cutting-spur; 5, the cutting-edge, and 6 the gimlet. These parts may all be of the ordinary or any preferred construction, as their specific construction has nothing to do with my present in vention. Upon one side of the pod, near the lower edge thereof, is an undercut crossgroove 7, within which the extension-piece 8 is adapted to slide. This piece is provided at its outer end with a cutting-spur 9, the lower edge thereof being beveled to form a cutting-edge 10.

Upon the face of the extension piece I preferably place gageunarks 11, for assistance in adjusting the extension-piece to bore any required diameter of hole, and on the beveled upper face thereof 1 form a series of notches or teeth 12.

Above the cross-groove 7 the side of the pod is cut away, this-cutaway portion being designated as 13, and extending upward therefrom isa vertical groove 14, the sides of which are straight, the upper end thereof being undercut, as indicated at 15.

16 denotes the locking-piece, which is shaped to correspond with cut-away portion 13, is provided with a shank 17, adapted to lie in groove 14:, and with a rounded upper end to engage the undercut end of groove 14, and the lower inner face of which is beveled, as at 19, and provided with notches or teeth, the said beveled face and notches being adapted to engage the corresponding beveled face and notches upon the extension -piece. A setscrew 21 passes through the locking-piece and engages the solid metal of the pod, as clearly shown in Fig. 3, thereby locking the extension piece at any desired position. WVhen it is required to bore a hole the regular gage of the bit, the extension-piece is not used, the set-screw being tightened up to hold the locking-piece in place. Suppose that it is desired to bore a hole of greater diameter than the regular gage of the bit. The set-screw is loosened and the extension-piece slid into place and set by the gage-marks to bore the required diameter of hole. The set-screw is then tightened up, forcing the notches or teeth upon the locking-piece to engage corresponding notches or teeth on the extensionpiece, thereby looking it firmly in place, so that it is impossible to move it in use, it being understood, of course, that the corresponding notches or teeth in the lockingpiece and the extension-piece are made to correspond with the gage-marks on the latter. Should it be desired to adjust the extensionpiece at any time, it can be done in an instant by simply giving the set-screw a slight turn backward to unlock the notches or teeth, then sliding the extension-piece to the required position, setting it by the gage-marks, and then giving the set-screw a slight turn forward to lock it in position.

Having thus described my invention, I claim 1. A bit having a cross-groove and cut away portion, and a vertical groove 14:, extending into the cut-away portion and undercut at its upper end, an extension-piece adapted to slide in the cross-groove, and a locking-piece lying in the cut-away portion and having a shank extending upward into the slot and engaging the undercut end thereof.

2. A bit having a cross-groove, cut-away portion, and slot 14,, under-cut at its upper end, an extension-piece outwardly beveled at its upper end and having; notches 12, and a I5 locking-piece lying in the out-away portion and having a shank engaging said grooves and undercut portion, the lower inner edge of said locking-piece being beveled and provided with notches adapted to engage notches 12. 20

In testimony whereof I affix my signature in presence of two witnesses.

WILLIAM S. VHITING. Vitnesses:

A. M. WoosTE-R, A. I. MUNSON. 

